1. Technical Field
The present disclosure relates to antireflection films and, particularly, to an antireflection film with low reflectance over a wide wavelength range and an optical element having the same.
2. Description of Related Art
Antireflection films have been extensively used in optical elements to reduce or even eliminate undesired light reflection. The challenge of utilizing such an antireflection film is: if the antireflection film is designed for use in visible light photography, reflectance of ultraviolet and infrared light may be very high, resulting in undesirable use in a wide wavelength range situation. For example, if the antireflection film is used in a wide-angle photography system, the reflectance characteristic curve of incident light with a great incident angle would shift towards the shorter-wavelength end of the optical spectrum. This causes great reflectance of red light with a large incident angle. As a result, color may be changed in images in wide-angle photography.
Therefore, it is desirable to provide an antireflection film with low reflectance over a wide wavelength range and an optical element having the same which can overcome the above-mentioned problems.